What is dining room size?

If you have a table that seats 8, the would be roughly 40 x 72. You would want 3 to 4 feet more on each side to allow for chairs and a path to get there. In addition, most hutches and credenzas are 24-36 inches wide. So, my guesstimate would be 12 ft x 20 ft. for a reasonably sized room.